Great Idea.
I have been using a 4"* 5/8" flat bar over the floor jack to bridge the chassis .The flat bar flexes but will take it but its always a bit of a drama..
Lifting with the flat bar option is a bit dodgy because you only have the steel on steel as slip restraint. I like this allot better because there is some lateral restraint if it moves laterally. The front is very difficult to jack. The beast is running 13 inch rims on the front so its lowww. Very difficult to get the jack in . I will have to check that the remaining room is enough for the slotted bar to fit above the jack. If there is I will make one up tomorrow.
Next stop is to dig a pit in the garage floor...!